--- a/hal/cocoa/CocoaSensor.mm
+++ b/hal/cocoa/CocoaSensor.mm
@@ -28,33 +28,41 @@ void UpdateHandler(nsITimer *aTimer, voi
   hal::SensorData sdata(hal::SENSOR_ACCELERATION,
 			PR_Now(),
 			values,
 			hal::SENSOR_ACCURACY_UNKNOWN);
   hal::NotifySensorChange(sdata);
 }
 
 void
-EnableSensorNotifications(SensorType aSensor) {
+EnableSensorNotifications(SensorType aSensor)
+{
+  if (aSensor != SENSOR_ACCELERATION)
+    return;
+
   if (sUpdateTimer)
     return;
 
   smsStartup(nil, nil);
   smsLoadCalibration();
 
   CallCreateInstance("@mozilla.org/timer;1", &sUpdateTimer);
   if (sUpdateTimer)
     sUpdateTimer->InitWithFuncCallback(UpdateHandler,
                                        NULL,
                                        DEFAULT_SENSOR_POLL,
                                        nsITimer::TYPE_REPEATING_SLACK);
 }
 
 void
-DisableSensorNotifications(SensorType aSensor) {
+DisableSensorNotifications(SensorType aSensor)
+{
+  if (aSensor != SENSOR_ACCELERATION)
+    return;
+
   if (sUpdateTimer) {
     sUpdateTimer->Cancel();
     NS_RELEASE(sUpdateTimer);
   }
   smsShutdown();
 }
 
 } // hal_impl